A Passive Optical Network (PON) can contain multiple Optical Line Terminals (OLTs), each connected by a shared optical fiber to a respective Optical Distribution Network (ODN) with multiple Optical Network Terminals (ONTs) on individual optical fibers. ONTs can malfunction and interfere with communications between the ONTs and the OLT on a shared optical fiber. Such malfunctions are generally the result of power outages or typical communication systems errors or failures. Other disruptions in communications can be caused by optical fibers being cut, such as by a backhoe. If ONTs are malfunctioning for any other reason, identifying the issue requires a technician to inspect each ONT, possibly causing costly interruptions to service.